Semiconductors and PN junctions Flashcards
Highest occupied energy band in metals is….
Not completely full
In insulators energy band is
Full
Distance between valence band and conduction band in different materials
No gap in metals
Small gap in semiconductors
Large gap in insulators
What does it mean for conduction and valence bands to be closer
Less energy required for electrons to move between them
How does LED emit light
When voltage applied causes electron to move towards conduction of p-type and away from n-type
They will combine with holes.
Electrons will drop from the conduction band to valence band
A photon will be emitted when electron drops, this photon will emit light.
How does temperature affect conductivity in semiconductors
It increases the conductivity
Effect of moving lamp closer to solar cell increases power output
Greater number of photons strike the solar cell per second
How does doping affect conductivity
Doping increases conductivity
